Process for removing fibrous layers from surfaces



Patented Sept. 1, 1936 PATENT OFFICE PROCESS FOR REMOVING FIBROUS LAYERS FROM SURFACES Martin Leatherman, Hyattsville, Md.

No Drawing.

Original application October 17, w r

1933, Serial No. 693,965. Divided and this ap-. plication April 6, 1984, Serial No. 719,340

2 Claims. (01. 87-5) (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) This application is a division of my application for patent which bears Serial Number 693,-

965 'filed October 17, 1933, covering a process and product for removing fibrous layers from surfaces.

This application is made under the act of March 3, 1883, as amended by the act of April 30, 1928, and the invention herein described if patented, may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon. My invention relates to the removal of fibrous layers from surfaces to which they are attached by an adhesive.

This invention is of. utility in connection with the removal of gummed labels, envelope flaps, stamps, or of wall paper from walls.

The fibrous layer may be of paper pulp, cloth or other material. Where the invention is applied to the removal of stamps, labels or envelope flaps, these are usuallyattached to the surface Wall to which they adhere with a dextrin paste. paper is usually attached to the wall with a starch paste. The invention is particularly useful in the removal of wall paper since the removal .of such paper involves considerable expense and time, and results often in injury'to woodwork or injury to the wall surface, and an accumulation of much dirt in the room where the work is proceeding.

The invention of which this is an improvement seeks to remove fibrous layers, especially wallpaper, easily and quickly by spraying or brushing thereon a gel consisting essentially of an aqueous gel of a hydrophilic coillold containing also a penetrant, that is some water soluble organic liquid penetrant, said gel imparting its moisture or liquid ingredients to the fibrous layer and thereby softening it suiiiciently to permit its easy removal. I have found that this ingenious invention can be greatly improved by certain modifications and additions of which this appli-. cation is a specification. 7

As is well known most fibrous layers are sized with water-resistant materials to lessen the water absorbing tendencies of said layers. This sizing may be of casein, starch, varnish or silicaceous material but in the case of wall paper, rosin mixed with aluminum resinate is predominately used. This sizing largely prevents the speedy soaking up'of the fibrous layers by water as itis ordinarily used to remove wall paper or other layers. The sizing also largely defeats the intended action of the gel in soaking up the paper -gel, since the process results in a lumpy product which thereafter, can only be brought to a proper 10 consistency by further treatment or the lapse of time.

I have discovered that if the hydrophllic colloid, such as bentonite and similar colloidal clays, in the dry state is mixed with the particular 15 penetrant utilized, a smooth paste is obtained. This paste is then added slowly to water in the proper amount as hereinafter explained. It is advisable to agitate the water while the paste is being added. The penetrant added to the colloid 20 in this manner forms an extremely satisfactory paste suspension of the gel material, which when poured into the water causes the gel material to be speedily and satisfactorily dispersed through the dispersing medium and thereby greatly as- 5 sists in the preparation of a smooth gel of uniform consistency. Also the gel material, or colloid, can be mixed with the penetrant and thereafter he added to the water as and when the gel is needed.

I have also found that either methyl or isopropyl alcohol is much better to use as a penetrant than ethyl alcohol because it has as great or greater penetrating properties and because its purchase is not hampered by any beverage and medicinal uses. However, my invention further mixture being then composed of the colloid, a

penetrant and a wetting agent. These so-called wetting agents produce a very great lessening in the surface tension of water and thereby produce spee y penetration of water into fibrous layers regardless of any sizing contained therein. Consequently these wetting agents-cause the water or softening agent to quickly travel from the gel into the fibrous layer. These wetting agents are alkali salts of sulionated organic materials and also alkali salts of sulfate esters of aliphatic 5o alcohols although the terms sulfonated and" suliated are used interchangeably. They are not precipitated or affected by salts occurring in hard water. or by those salts which commonly occur as impurities inbentonite. They are notacid or alkaline in their reaction to any appreciable extent and are not injurious to wood or other finishes. Among the wetting agents which I find of great value are sulfonates of the type of isopropyl naphthalene sulphonic acids or salts of these acids of the type as'illustrated by the general formula R-C1oHe-SO3N8' in which R represents the side chain carbon group; sulfonated pine oil where the active ingredients are probably sulfonates of alpha and beta terpineols, of fenchyl alcohol and of bomeol; and more especially salts of sulfonates of higher fatty alcohols, particularly lauric alcohol, of which the following is a type formula:

H B(J-O-S0r0 Na i I in which It may represent any aliphatic hydrocarbon cha'in containing 11 or more carbon atoms,

but for the purposes of this invention I prefer to use a material in which R represents as great a predominance of 11 carbon atom chains as possistency which maybe applied either with a brush or with a sprayer andconsequently the proportions of some or all of the constituents may vary widely and still be satisfactory under the varying conditions of use. However, as an illustration of one composition which I have found satisfactory I may use one gram of sulfonated pine oil and one gram of sodium lauryl sulfate seven to nine grams of bentonite and ten to twelve cubic centimeters of isopropyl alcohol or methyl alcohol, the whole stirred together into a smooth flowing paste or slurry which when ready for application to wall paper or other fibrous layers is poured into one hundred cubic centimeters of water. It is obvious that I may vary these proportions widely within the spirit of my invention.

I may substitute two grams of sodium lauryl sul-' fate for the mixture of sulfonated pine oil and sodium lauryl sulfate or I may find it advantageous to use entirely different wetting agents and to completely change the proportions used. I may use acetone, or alcohols such as ethyl or propyl, or ethylene glycol, in place of methyl or isopropyl alcohol, and I may vary the amounts I use of the organic liquids or penetrants. I may vary the amounts of bentonite or of water depending upon conditions. Finally, of course, the'respective proportions can be multiplied any number of times to obtain any quantity desired.

Where only one layer of fibrous material is to be removed I may increase the proportion of water very greatly since only a small amount of moisture is required to soak up one layer and it is not necessaryto hold a thick layer of gel on the surface; Again, where several layers of heavy fibrous material of high absorptive capacity must be soaked up I will want to get enough softening liquid on the outer surface at one application to soak entirely through the several layers. To

this end I will make the gel thick enough to hold as thick a'layer of gel on the surface as may be required to furnish the requisite quantity of softening-liquid for soaking up all the layers present. Even a relatively non-flowing gel of the type I employ will contain more than eighty-five per cent of softening liquid. V a

By softening liquid I refer to any liquid which .is capable of softening adhesives used for holding fibrous layers on surfaces. Ordinarily the softening liquid will be a mixture of water and an organicliquid such as isopropyl alcohol in which mixture is dissolved a suitable wetting agent. The gel material will usually be bentonite but it may be any material which is capable of binding the softening liquid into a gel of the desired state of plasticity.

' Under some conditions I may find it advisable to use a pigment or dye in my gel to assist even application of the gel to the fibrous layers.

I do not wish to be limited to the exact ingredients or proportions thereof which I have specified and desire that I be limited only by the showing of the prior art and the scope of the appended claims, and that I be allowed the full range 0 equivalents in interpretation thereof.

Having fully disclosed my discovery, I claim:

1. The process of removing fibrous layers from surfaces to which they are attached with an adhesive which comprises preparing a gel by mixing thoroughly, dry bentonite, methyl alcohol, sulfonated pine oil, the sodium salt of sulfonated lauryl alcohol and a coloring material, in proportions to form a pasty mass, and thereafter adding this mixture to water, applying the resulting gel 3 to the surface of the fibrous layer, allowing the gelto remain on the fibrous layer until the adhesive becomes softened and then removing the fibrous layer from the surface.

2. The process of removing fibrous layers from surfaces to which they are attached by an adhesive which comprises preparing a gel by mixing thoroughly, dry bentonite, methyl alcohol and the sodium salts of sulfated lauryl alcohol in proportions to make a slurry and thereafter adding this slurry to water, applying the resulting gel to the surface of the fibrous layers, allowing the gel to' remain on the-fibrous layers until the; adhesive becomes softened and then removing'thefibrous layers from the surface.

MAR'I'IN LEA'I'HERMAN; 

